This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. NLSL.SRLS.EXCH is a computer program for simulating multi-frequency CW spectra based on slowly relaxing local structure (SRLS) model with dynamic exchange. A service request was received from Dr Yuri Nesmelov on the usage of the NLSL.SRLS.EXCH program from ACERT website to study protein dynamics undergoing conformation exchange.